Copper-Tin Alloys: The Bronzes Copper-Tin Alloys: The Bronzes Abstract: The important alloys of copper and tin from an industrial point of view are the bronzes comprised within certain limits of tin content. As in the case of the brasses, the addition of tin to copper results in the formation of a series of solid solutions. The addition of tin to copper results in the formation of a series of solid solutions which, in accordance with usual practice, are referred to in order of diminishing copper content as the á, â, a, etc., constituents. The important alloys of copper and tin from an industrial point of view are the bronzes comprised within certain limits of tin content. As in the case of the brasses, the addition of tin to copper results in the formation of a series of solid solutions. The constitutional diagram of copper-tin alloys is very complex, but that part of it which deals with alloys of industrial importance is reproduced in Fig. 1. Figure 1.

Constitutional Diagram of the Copper-Tin Alloys The addition of tin to copper results in the formation of a series of solid solutions which, in accordance with usual practice, are referred to in order of diminishing copper content as the á, â, a, etc., constituents. The diagram may be summarized as follows: Percentage composition Constituent just below the freezing point Constituent after slow cooling to 400°C Copper â–>(á + â) á + ä Further changes on cooling from 400°C to room temperature are so sluggish that they only occur in conditions very far removed from actual practice. The á solution is the softest of the constituents; it may be rolled or stamped cold, but it hardens under this treatment much more rapidly decreases than á-brass. The â and a constituents do not exist in the alloy slowly cooled to room temperature: this is due to successive changes occurring at 586°C and 520°C whereby â is resolved into á +a and a into á + ä. The ä constituent has the crystal structure of a-brass. It has a narrow range of composition corresponding approximately to the formula Cu3lSn8 and, like all intermetallic compounds, is extremely hard and brittle.

The ä -> (á + l) change at 350°C does not occur in commercial practice, though alloys richer in tin may contain the a constituent, which corresponds to Cu3Sn, and the ç solid solution, which approximates to the composition CuSn. 95:5 Copper-Tin Alloy On cooling from the liquid condition, the solid solution which first forms contains only about 2 percent of tin. Thus the cast metal has a cored structure and the coring is very marked because of the long range between liquidus and solidus; but it may be eliminated by diffusion on cooling more slowly or by annealing. Any absorption of oxygen occurring during manufacture results in the presence of SnO2 in the alloy, tending to make it brittle. A deoxidizer such as zinc is therefore frequently added. The addition of zinc, as in coinage bronze, causes no change in the microscopical appearance of the homogeneous á constituent. The zinc, however, exerts its deoxidizing effect in the liquid, and slight hardening effect on the solid solution. The structure of a bronze coin shows marked deformation of the crystals. On annealing, recrystallization takes place with subsequent crystal growth.

Twinning is a characteristic feature of the cold-worked and annealed alloy. 90:10 Copper-Tin Alloy This is typical gun-metal, most varieties of which, however, contain a deoxidizer, frequently zinc (e.g. Admiralty gun-metal, copper 88%, tin 10%, zinc 2%). The structure of the cast material depends on the rate of cooling, both through the range of solidification and below. On account of the wide solidification range of the alloy and the slow rate of tin diffusion, the apparent solubility limit of the á solution is well below that shown in the diagram. The cast structure is always definitely dendritic and if coring is pronounced, some â solution may be formed at 798°C This interdendritic â, on cooling, gives rise to the hard ä constituent. On the other hand, after slow cooling or prolonged annealing, the homogeneous á constituent may be produced. A chill-cast gun-metal will therefore be very different in structure and properties from one which has been annealed.

85:15 Copper-Tin Alloy This chemical composition is typical for a number of bronzes used as bearing metals, most of which, however, contain a little zinc as a deoxidizer. It is also the approximate composition of bell metal. Immediately after solidification the alloy consists of the á and â constituents. If rapidly cooled, these are preserved. If slowly cooled, the â (or a) is completely broken down below 520°C into a complex á + ä. The á + â structure is being replaced by á + (á + ä) complex in the slowly cooled alloy. This accounts for the fact that sand castings of this alloy are much harder than chill castings. It also provides the basis of heat treatment method, applied in the one case to bells and in the other to bearing metals. Date Published: Mar-2003 Alloys Alloys Alloys Alloys Copper’s performance can be expanded to suit many industrial applications. This is achieved by alloying: making a solid material out of two or more different metals. By combining copper with other metals, alloys can be made to fit almost any application.

The Copper Alloys Tree There are more than 400 copper alloys, each with a unique combination of properties, to suit many applications, manufacturing processes and environments. Pure copper has the best electrical and thermal conductivity of any commercial metal. Today, over half of the copper produced is used in electrical and electronic applications and this leads to a convenient classification of the types of copper into electrical (high conductivity) and non-electrical (engineering). Read more . Copper forms alloys more freely than most metals and with a wide range of alloying elements to produce the following alloys: Brass is the generic term for a range of copper-zinc alloys with differing combinations of properties, including strength, machinability, ductility, wear-resistance, hardness, colour, antimicrobial, electrical and thermal conductivity, and corrosion-resistance. Read more. Bronze alloys are made from copper and tin, and were the first to be developed about four thousand years ago. They were so important that they led to a period in time being named the Bronze Age. Read more . Gunmetals are alloys of copper with tin, zinc and lead and have been used for at least 2000 years due to their ease of casting and good strength and corrosion resistance. Read more .

Copper-nickel alloys have excellent resistance to marine corrosion and biofouling. The addition of nickel to copper improves strength and corrosion resistance, but good ductility is retained. Read more . Nickel silver alloys are made from copper, nickel and zinc, and can be regarded as special brasses. They have an attractive silvery appearance rather than the typical brassy colour. Read more . Beryllium copper is the hardest and strongest of any copper alloy, in the fully heat treated and cold worked condition. It is similar in mechanical properties to many high strength alloy steels but, compared to steels, it has better corrosion resistance. Read more . Related Resources Pub TN44 - Machining Brass, Copper and Copper Alloys £ 0.00 Design and manufacture alloys, brass, coppers, design, Industry, machining, manufacturing Detailed advice on machining as a production technique. Guidance on materials selection where good machinability is important. Basic information and guidance for those who know what material is to be machined. Advice on the selection of cutting fluids. 1992. 65pp.

Pub TN27 - High Conductivity Coppers: Technical Data Electrical systems alloys, conductivity , coppers, electrical, property, standards, technical These data sheets, originally published in a series from 1968 - 1972, cover all the main coppers and copper alloys. They contain an invaluable summary of data relating to the physical and mechanical properties of the materials at low, ambient and elevated temperatures which is not available elsewhere. Pub TN26 - Brasses, Nickel Brass and Nickel Silver - Technical Data Design and manufacture alloys, brass, Industry, manufacturing, nickel silver, property, sheet , technical These data sheets, originally published 1968 - 1972, contain an invaluable summary of data relating to the physical and mechanical properties of the materials at low, ambient and elevated temperatures which is not available elsewhere. Pub 225 - Copper Alloys in Seawater: Avoidance of Corrosion Marine alloys, bronze, copper-nickel, corrosion, gunmetal, property, seawater Practical guidance for engineers on the avoidance of corrosion in copper alloys for seawater applications. 2016. 20 pp.

Pub 223 - Copper for Contacts Electrical systems alloys, applications, contacts, coppers, electrical This publication looks at the properties required for contact materials, and to identify those applications in which copper or copper alloys have special advantages. 1980, revised 2015. 36pp. Pub 214 - Antimicrobial Copper Alloys: Guidance for Selection Healthcare alloys, antimicrobial, care homes, design, designer, hospital, property This publication offers designers, manufacturers and specifiers guidance on identifying the most appropriate copper alloy for a product. The guide features a table of commonly available alloys, representing the different copper-alloy families, listing compositions and properties and ordered by colour. 2013. 16pp. Pub 206 - Copper Alloys in Marine Environments Design and manufacture, Marine alloys, beryllium, brass, bronze, copper-nickel, corrosion, marine, property, resistance, seawater This publication focuses on the properties and corrosion resistance of a wide range of copper alloys used for seawater service - ranging from commercial grades of copper through copper-nickels, bronze, brass and copper beryllium.

It allows the reader to understand potential types of corrosion mechanisms for the different alloy types and how to avoid them. 2012. 32pp. Pub 202 - Practical Aspects of Reducing Bioburden with Copper: Clinical Case Study: Selly Oak Hospital, Birmingham Healthcare alloys, antimicrobial, clinical trial, healthcare-associated infections, hospital, infections, installation, pathogenic microbes, touch surface The clinical trial at Selly Oak Hospital demonstrated a 90-100% reduction in contamination on copper-containing vs standard surfaces. The experience of fitting out the test ward with copper-containing products has made a major contribution to the understanding of the practical application of the science. October 2009. 4pp. Pub 198 - The Benefits of Designing with Antimicrobial Copper Alloys Healthcare alloys, antimicrobial, care homes, design, designer, healthcare-associated infections, hospital, infections, touch surface Introductory brochure for architects and designers providing an overview on using the inherent antimicrobial property of copper to design out infection in critical environments such as hospitals and care homes, where touch surfaces can act as reservoirs for dangerous germs. Updated May 2013. 2pp.

Pub 177 - Brass in Focus Design and manufacture alloys, brass, design, designer, engineer, products Brasses are versatile and cost-effective materials, ideal for designing complex and long lasting components. Article by Ken Kempson in May/June 2004 issue of Engineering Designer. 2004. 4pp. PAGE 1 / 6 No other metal has a range of attractive colours comparable to copper and its alloys. The red of copper, the gold of the brasses and aluminium bronzes, the chocolate-brown of manganese bronzes, the green patina and the shiny white nickel-silver enable designers to exploit copper in infinite ways. bronze | alloy | Britannica.com Bronze Earth Bronze, alloy traditionally composed of copper and tin . Bronze is of exceptional historical interest and still finds wide applications. It was made before 3000 bc, though its use in artifacts did not become common until much later. The proportions of copper and tin varied widely (from 67 to 95 percent copper in surviving artifacts), but, by the Middle Ages in Europe, certain proportions were known to yield specific properties. An alloy described in an 11th-century Greek manuscript in the library of St.

Mark’s, Venice, cites a proportion of one pound copper to two ounces of tin (8 to 1), approximately that used for bronze gunmetal in later times. Some modern bronzes contain no tin at all, substituting other metals such as aluminum, manganese , and even zinc . Bronze Lion Monument on the Burgplatz, in Braunschweig, Ger. H. Krause-Willemberg/ZEFA Bronze is harder than copper as a result of alloying that metal with tin or other metals. Bronze is also more fusible (i.e., more readily melted) and is hence easier to cast. It is also harder than pure iron and far more resistant to corrosion . The substitution of iron for bronze in tools and weapons from about 1000 bc was the result of iron’s abundance compared to copper and tin rather than any inherent advantages of iron. copper processing: History Bell metal, characterized by its sonorous quality when struck, is a bronze with a high tin content of 20–25 percent. Statuary bronze, with a tin content of less than 10 percent and an admixture of zinc and lead , is technically a brass .

Bronze is improved in hardness and strength by the addition of a small amount of phosphorus; phosphor bronze may contain 1 or 2 percent phosphorus in the ingot and a mere trace after casting, but its strength is nonetheless enhanced for such applications as pump plungers, valves, and bushings. Also useful in mechanical engineering are manganese bronzes , in which there may be little or no tin but considerable amounts of zinc and up to 4.5 percent manganese. Aluminum bronzes, containing up to 16 percent aluminum and small amounts of other metals such as iron or nickel , are especially strong and corrosion-resistant; they are cast or wrought into pipe fittings, pumps, gears, ship propellers, and turbine blades. Similar Topics Tin and Tin Alloys Tin and Tin Alloys Abstract: Tin was one of the first metals known to man. Throughout ancient history, various cultures recognized the virtues of tin in coatings, alloys and compounds, and use of the metal increased with advancing technology. Today, tin is an important metal in industry even though the annual tonnage used is much smaller than those of many other metals.

One reason for the small tonnage is that, in most applications, only very small amounts of tin are used at a time. Tin was one of the first metals known to man. Throughout ancient history, various cultures recognized the virtues of tin in coatings, alloys and compounds, and use of the metal increased with advancing technology. Today, tin is an important metal in industry even though the annual tonnage used is much smaller than those of many other metals. One reason for the small tonnage is that, in most applications, only very small amounts of tin are used at a time. Tinplate. The largest single application of tin is in manufacture of tin-plate (steel sheet coated with tin), which accounts for about 40% of total world tin consumption. Since 1940, the traditional hot dip method of making tinplate has been largely replaced by electrodeposition of tin on continuous strips of rolled steel. Electrolytic tin-plate can be produced with either equal or unequal amounts of tin on the two surfaces of the steel base metal. Nominal coating thickness for equally coated tinplate range from 0.38 to 1.54 µm on each surface.

The thicker coating on tinplate with unequal coatings (differential tinplate) rarely exceed 2.0 µm. Tinplate is produced in thickness from 0.15 to 0.60 mm. Over 90% of world production of tinplate is used for containers (tin cans). Tinplate cans find their most important use in packaging of food products, beer and soft drinks, but also are used for holding paint, motor oil, disinfectants, detergents and polishes. Other applications of tinplate include fabrication of signs, niters, batteries, toys, gaskets, and containers for pharmaceuticals, cosmetics, fuels, tobacco and numerous other commodities. Electroplating accounts for one of the major uses of tin and tin chemicals. Tin is used in anodes, and tin chemicals are used in formulating various electrolytes, for coating a variety of products. Tin electroplating can be performed in either acid or alkaline solutions. Sodium or potassium stan-nates form the bases of alkaline tin plating electrolytes that are very efficient and capable of producing high-quality deposits. Hot Dip Coatings. Coating of steel with lead-tin alloys produces a material called tern plate.

It is easily formed and easily soldered and is used as a roofing and weather sealing material and in construction of automotive gasoline tanks, signs, radiator header tanks, brackets, chassis and covers for electronic equipment and sheathing for cable and pipe. Hot dip tin coatings are used on wire for component leads as well as food handling and processing equipment. Unalloyed Tin. There are only a few applications where tin is used unalloyed with other metals. Unalloyed tin is well recognized as the most practical lining material for handling high-purity water in distillation plants because it is chemically inert to pure water and will not contaminate the water in any way. Tin in Alloys. Solders account for the second largest use of tin (after tinplate). Tin is an important constituent in solders because it wets and adheres to many common base metals at temperatures considerably below their melting points.Tin is alloyed with lead to produce solders with melting points lower than those of either tin or lead. Small amounts of various metals, notably antimony and silver, are added to tin-lead solders to increase their strength. These solders can be used for joints subjected to high or even subzero service temperatures.

Both solder compositions and applications of joining by soldering are many and varied. Commercially pure tin is used for soldering side seams of cans for special food products and aerosol sprays. The electronics and electrical industries employ solders containing 40 to 70% tin, which provide strong and reliable joints under a variety of environmental conditions. General-purpose solders (50Sn-50Pb and 40Sn-60Pb) are used for light engineering applications, plumbing and sheet metal work. Lower-tin solders (20 to 35% Sn, remainder Pb) are used in joining cable and in production of automobile radiators and heat exchangers. Low-tin solders are used in large amounts to fill crevices at seams and welds in automotive bodies, thereby providing smooth joints and contours. Solders containing about 2% tin (remainder lead) are used for can side seams to provide hermetic seals. Tin-zinc solders are used to join aluminum, while tin-antimony and tin-silver solders are employed in applications requiring joints with high creep resistance. Alloys for Organ Pipes. Tin-lead alloys are used in the manufacturing of organ pipes.

These materials commonly are named "spotted metal" because they develop large nucleated crystals or "spots" when solidified as strip on casting tables. The pipes that produce the diapason tones of organs generally are made of alloys with tin contents varying from 20 to 90% according to the tone required. Pewter is a tin-base white metal containing antimony and copper. Originally, pewter was defined as an alloy of tin and lead, but to avoid toxicity and dullness of finish, lead is excluded from modern pewter. These modem compositions contain 1 to 8% antimony and 0.25 to 3.0% copper. Bearing Materials. Tin has a low coefficient of friction, which is the first consideration in its use as a bearing material. Tin is structurally a weak metal, and when used in bearing applications it is alloyed with copper and antimony for increased hardness, tensile strength and fatigue resistance. Normally, the quantity of lead in these alloys, called tin-base babbits, is limited to 0.35 to 0.5% to avoid formation of the tin-lead eutectic, which would significantly reduce strength properties at operating temperatures.

Lead-base bearing alloys, called lead-base babbits, contain up to 10% tin and 12 to 18% antimony. In general, these alloys are inferior in strength to tin-base babbits, and this must be equated with their lower cost. Bearing alloys must maintain a balance between softness and strength. Aluminum-tin bearing alloys represent an excellent compromise between the requirements for high fatigue strength and the need for good surface properties such as softness, seizure resistance and embed ability. Aluminum-tin bearing alloys are usually employed in conjunction with hardened steel or ductile iron crankshafts and allow significantly higher loading than tin- or lead-base bearing alloys. Low-tin aluminum-base alloys (5 to 7% Sn) containing small amounts of strengthening elements, such as copper and nickel, are often used for connecting rods and thrust bearings in high-duty engines. Strict dimensional tolerances must be adhered to and oil contamination should be avoided. Alloys containing 20 to 40% tin, remainder aluminum, show excellent resistance to corrosion by products of oil breakdown and good embeddability, particularly in dusty environments.

The higher-tin alloys have adequate strength and better surface properties, which make them useful for crosshead bearings in high-power marine diesel engines. Battery-grid Alloys. Lead-calcium-tin alloys have been developed for storage-battery grids largely as replacements for antimonies lead alloys. Use of ternary lead-base alloys containing up to 1.3% tin has substantially reduced gassing, and therefore batteries whose grids are made of these alloys do not require periodic water additions during their working life. Two chief methods of grid manufacture are casting and fabrication of wrought alloys including punching, roll forging and expanded metal processes. Copper Alloys. Copper-tin bronzes were some of the first alloys used by man, and these alloys continue to be used for structural and decorative purposes. True bronzes contain tin in amounts up to 10% as well as very small amounts of phosphorus. Quaternary bronzes containing 5% Sn, 5% Zn, 5% Pb, and remainder Cu are used for general-purpose castings for applications requiring reasonable strength and soundness, such as gears, pumps, and automotive fittings. Dental alloys for making amalgams contain silver, tin, mercury, and some copper and zinc.

The copper increases hardness and strength and the zinc acts as a scavenger during alloy manufacture, protecting major constituents from oxidation. Most dental alloys presently available contain 25 to 27% tin and consist mainly of the inter-metallic compound Ag and Sn. When porcelain veneers are added to gold alloys for high-grade dental restoration, 1% tin is added to the gold alloy to ensure bonding with the porcelain. Titanium Alloys. Tin strengthens titanium alloys by forming solid solutions. Titanium can exist in the low-temperature alpha phase or the higher-temperature beta phase, which remains stable up to the melting point. In titanium alloys, relative amounts of alpha and beta phases present at the service temperature have profound effects on properties. Aluminum additions raise the transformation temperature and stabilize the alpha phase, but may cause embrittlement in amounts greater than 7%. However, with tin additions, increased strength without embrittlement can be obtained in aluminum-stabilized alpha titanium alloys. Optimum strength and workability can be obtained with 5% aluminum and 2.5% tin; in addition, this alloy has the advantage of being weldable.

Date Published: Sep-2001 History of Common Metals: Copper, Lead, Iron, Tin, Aluminum Community History of Metals Such as Copper, Lead, Iron, Tin, & Aluminum Throughout history, man has harnessed the power of metals to make tools, steel buildings, instruments of war, aid in medicine and create innovations that have advanced humankind. The common metals copper, lead, iron, tin and aluminum have been central to these innovations. Each with their own unique history, these five common metals changed civilizations, funded empires and have become a part of our everyday lives. Copper Copper, a soft and malleable metal, has been used for at least 10,000 years. First discovered around 9000 BC in the Middle East, knowledge of copper smelting spread around the world to China around 2800 BC, Latin America before 600 AD and in Sub-Saharan Africa around 900 AD. The extraction of copper was essential to the discovery of other metals, such as iron and bronze. As early as 3000 BC, Sumerians and Egyptians were using copper alloyed with tin to create bronze.

The metal was a vital resource for both Greeks and Romans. Known by the Romans as "cyprium," the metal was named after the island of Cyprus, where the majority of Roman copper was mined. Later, the term was modified to become "cuprum," the basis of the English term "copper." The metal was used as currency throughout the Roman Empire from the 6th through 3rd centuries BC, with the faces of emperors imprinted on each coin. Associated with Venus and Aphrodite, the goddesses of love, copper was revered for its beautiful warm color and luster. Use of copper spread around the world in the following centuries. Brass, an alloy of tin and copper, was discovered in the British Isles during the 3rd century BC and copper extraction began in North America around 800 AD. In 1830, German chemist Gottfried Osann developed a powder metallurgy technique that revolutionized the use of copper in manufacturing. The next major innovation occurred in 1949, when the Finnish company Outokumpu invented a flash smelting process that rapidly accelerated the production of copper. Today, the majority of copper is used in electrical wires, roofing, machinery and plumbing.

5% of the world's copper is currently used in combination with brass or bronze to create a more resilient alloy. Lead Like copper, lead is a malleable metal with a history spanning centuries. Widely available and simple to extract, the metal was The earliest known lead artifacts, beads found in the Catalhoyuk region of what is today Turkey, date back to 6400 BCE. The Roman Empire was the largest producer of lead in the ancient world. Romans produced nearly 80,000 metric tons of the metal annually through their mining endeavors in Central Europe, the Balkans, Asia Minor, Greece and the British Isles. The mines in Hispania were particularly active, producing nearly 40% of all lead at the time. Lead was used by the Romans in the construction of monuments, statues and buildings. The metal was formed into pins used to secure limestone bricks. Associated with the planet Saturn by alchemists whose main goal was to turn lead into gold, the metal was believed to be the oldest metal and was symbolized by a scythe. Centuries later in 1951, Nobel Laureate chemist Glenn Seaborg succeeded in turning a small quantity of lead into gold.

The metal's abbreviation "Pb" stems from the Latin "plumbum," meaning "soft metal." The modern English terms "plumber" and "plumbing" stem from this root as well. Today, lead is widely used in plumbing, bullets, batteries and in numerous alloys. Iron Iron is the planet's most common element, forming large portions of both the inner and outer core of Earth. Beads dating from 3500 BC found in Egypt contained a relatively large percentage of nickel. The presence of nickel indicates that the iron was of meteoric origin, which was revered because it came from the heavens. Believed to be a blessed metal, this iron was commonly used to create tools use in both religion and war. Weapons made of iron were superior to those made of bronze because of their higher durability and rust resistance. Production of iron was not realized until the Middle Bronze Age and it took hundreds of years for the metal to become prominent throughout the world. Early iron production took place in what is now Syria around 2700 BC when the Hittites began to develop mines. The practice of smelting iron spread from there throughout the Middle East, leading to the dawn of the Iron Age around 1300 BC.

The development of iron ore and its resulting innovations gave rise to Celtic expansion in Europe and aided in the growth of the Roman Empire. Centuries later, British chemist Henry Cort's discovery of the process to create wrought iron and Abraham Darby's invention of a blast furnace which created cast iron helped spark the Industrial Revolution during the late 18th century. Iron is still the most commonly used metal today. Different types of the metal are used to create stainless steel, ammonia, paint, circuit boards and other objects used in modern daily life. Tin Tin's history dates back to the Bronze Age. This common metal was used to create bronze as early as 3000 BC in the Middle East and Balkans. The earliest known use of tin in Europe was in 2500 BC in the Erzegebirge region, which today lies between Germany and the Czech Republic. Knowledge of mining the metal spread from there around 2000 BC to the British Isles and Iberian Peninsula. Deposits throughout the continent were heavily exploited under the Romans. During the Medieval era, British deposits replaced those of the Iberian Peninsula and Germany as main producers of tin.

Other large deposits were later discovered in Sub-Saharan Africa, Central and South America, Southeast Asia and Australia. Today, most of the world's tin originates from Bolivia, the Republic of the Congo, China, Thailand, Indonesia and Malaysia. Tin is used in many common objects like cans, kitchen utensils, decor, wrappings, circuits and even toothpaste. Aluminum Aluminum, another common metal, was used by Greeks and Romans as an agent to set dye onto fabrics and as an astringent for cleaning wounds. The metal is still used today as styptic agent, used to stop bleeding. French chemist Guyton de Morveau called the metal "alumni" when he experimented with it in 1761 and British chemist Humphry Davy first coined the term "aluminum" in 1808. Danish chemist Hans Christian Orested built on the work of Moveau and Davy and is credited with isolating aluminum in 1825. Two years later, German chemist Friedrick Wohler was credited with the discovery of aluminum after creating the metal by mixing anhydrous aluminum chloride and potassium.

Before improvements made by Charles Martin Hall and Paul Heroult in the late 1880s, aluminum's very difficult extraction process made the metal more costly than gold. Aluminum was still more valuable than silver when it was chosen to top the Washington Monument in 1884. Thanks to additional innovations in processing, aluminum is more affordable and very common. The metal is now used in a variety of ways, such as in consumer products, glass, packaging, transportation, windows, gutters, kitchen utensils and outdoor furniture. These five common metals have revolutionized the way people work, travel, build homes, and spend their leisure time. Their long histories from simple ores to complex machines and objects are a testament to mankind's innovative spirit. Category: Tin Alloy Tin Alloy Do You Know ? An alloy of 80% gold 20% tin melts at around 280°C this would easily allow casting into rubber molds! This alloy is used as a special solder and has a slight green color. An alloy of tin, bismuth, lead and cadmium in the right proportions will melt well below the boiling point of water at just 70C. Tin is one of the earliest metals discovered by human being.

Tin is known for a low-melting point (450°F) and its fluidity. It's very easy to form tin alloy with other metals because of its softness and formability. The metal has a high boiling point and is nontoxic and solderable. The difference of temperature between melting and boiling points, which is important for castings, is greater than all other metals. Different casting methods used for tin alloy casting are gravity die casting, pressure die casting, and centrifugal casting. As there is little or no shrinkage occurs on solidification, components produced by tin-alloy castings are sound and dimensionally accurate. The design of molds should be such that sufficient amount of metal is fed to inside corners of the mold cavity. Carbon-steel or rubber molds can be used as tin alloys have low-melting points. Property Electrical resistivity at 20 0C 12.6µ cm Though, little bit expensive, tin is considered to be the perfect metal for casting. As the melting temperature is fairly low, simple molds, even molds made of special rubber can be used. Unlike lead, tin is non-toxic and it's shiny and doesn't tarnish.

Types and Features of Tin Alloys Pewter It contain 1-8% antimony and 0.5- 3% copper. Excellent castability and workability. For spun pewter products, antimony content is usually below 7%, and pewter casting alloys contain 7.5% antimony and 0.5% copper. Due to its excellent drawing and spinning properties, wrought parts are usually made from pewter that is first cast into slabs, then rolled into sheet. Bearing alloys Bearing alloys are low-friction materials. May hold high percentages of aluminum (to 80%), antimony (to 10%), or copper (to 10%). These alloys also contain babbitt metal, aluminum-tin, and bronze. Steel, cast iron, or bronze backing materials are used to strengthen its low mechanical strength. Bearing alloys are corrosion resistant, soft and comfortable. Bronzes Bronzes are alloys of copper and tin. Commercial grades usually contains 3-8% tin for wrought products and up to 12% for cast products. Gunmetals are bronzes, which also contain zinc.

Die-casting tin-based alloys It has low melting temperatures, usually below the solidus of eutectic-base tin-lead solders (361°F). Main alloying elements include bismuth, lead, cadmium, and indium. Generally, Fusible tin alloys provide electrical or mechanical links in safety devices. These alloys have applications in low-temperature solders, seals for glass and other heat-sensitive materials, foundry patterns, molds for low-volume production of plastic parts. Tin and tin-alloy powders Tin and tin-alloy powders are produced by atomization techniques. These powders are available in a number of mesh sizes. It has applications in the manufacture of powder-metallurgy parts, in the spray metalization of surfaces, and in tinning and solder pastes. Casting Alloys Copper and Copper Alloys | Evans Findings Copper and Copper Alloys These sprinkler activators are copper with a tin plating. Copper and its alloys are widely used in deep draw and flat stamped products because they have excellent electrical and thermal performance, good resistance to corrosion, high ductility and relatively low cost. Copper is non-magnetic, non-sparking and non-bacterial.

Because it is low in the reactivity series, it is slow to corrode. With medium strength and high fatigue resistance, copper and its alloys are primary metals for electrical applications. Copper has a density of 8.94 g/cm3 , or .323 lb/cu.in., elastic modulus of 115 GPa, or 17x 10^6 psi, and melting temperature 1083°C, or 1981°F. With a thermal conductivity of about 231 BTU/ (hr-ft- deg F), it is 30 times more conductive than steel. Copper Alloys – Brass, Bronze, ComBro, Phos Bronze, BeCu, Cupro Nickel While copper, used for 10,000 years, is one of mankind’s first metals, bronze, in use for over 5,000 years, is no youngster. It is considered the world’s first alloy, predating brass by three millenia. Brass objects have been found in the homes of ancient Rome, dating back to 100 B.C. but not before.

Bronze is copper alloyed with tin or zinc – usually 90%, or more, copper. Brass is copper alloyed with zinc – most commonly with 30 percent zinc. Red brass is most commonly 15 percent zinc. CuproNickel — Cu + Ni — may be 69.4% to 96% copper. Standard CuproNickelTin C70260 is 97% copper, 2% tin, 0.5% silicon. Brass, Bronze, and Phos Bronze (Cu-Sn-P) are commonly used in both deep drawn and flat stamped components. Commercial bronze, “combro”, is most commonly 90% Copper- 10% zinc alloy and has good applications as a connector. BeCu — a Copper Beryllium alloy known as Beryllium Bronze, is commonly used in hermetic seals because the alloy has nearly the same thermal expansion as the glass used in those seals. As the glass expands and contracts, the metal expands and contracts equally so the glass does not crack.

Of the roughly 16 basic types of wrought copper alloys, fewer than half are commonly used for making small stamped and drawn parts, especially for electrical and electronic conductors and contacts. In some cases we have these products heat treated and/or plated with coatings, like tin, after forming. Markets Copper: An Ancient Metal - Dartmouth Toxic Metals Superfund Research Program Copper: An Ancient Metal Copper: An Ancient Metal Humans Meet Metal Between seven and ten thousand years ago, our early ancestors discovered that copper is malleable, holds a sharp edge, and could be fashioned into tools, ornaments, and weapons more easily than stone, a discovery that would change humanity forever. This meeting of humans and metals would be the first step out of the Stone Age and into the ages of metals: the Bronze and Iron Ages. Thus began the increased movement of elements and minerals out of their parent geological formations and into the air, soil, water, and living organisms by way of smelters, furnaces and mine tailings. The first several thousand years of copper production contributed little to global or even local pollution.

Copper is not very toxic in comparison to other metals and early humans used too little of it to begin concentrating it in soil, air, or water to the extent that it would affect human health or ecosystems. It appears that during the first few thousand years of its use, humans experiment with and learned techniques to utilize copper. As they got better at working with it, civilizations became more complex, which in turn often enabled better copper-working technology. With this came expanded use of copper and a greater movement of copper into our everyday environment. Metallurgy is Born Gold is believed to have been used earlier than copper, though its softness and scarcity made it impractical for widespread use, whereas copper is harder and found in pure form (native copper) in many parts of the world. (Gold and copper's distinct colors and existence in pure form made it easy for our early ancestors to distinguish the two metals from other minerals and stones they came across.) There is disagreement among archaeologists about the exact date and location of the first utilization of copper by humans.

Archaeological evidence suggests that copper was first used between 8,000 and 5,000 B.C., most likely in the regions known now as Turkey, Iran, Iraq and  toward the end of that period  the Indian subcontinent. Archeologists have also found evidence of mining and annealing of the abundant native copper in the Upper Peninsula of Michigan in the United States dating back to 5,000 B.C. Native copper was likely used first, as it did not require any process to purify it. It could have been hammered into shapes although it would have been very brittle. Annealing was the first step toward true metallurgy, when people discovered that copper became more flexible and easy to work with when it was heated before hammering. Next, casting of molten copper into molds was developed. At some point humans discovered copper ore and  possibly by accident  that the ore could be heated to very high temperatures in a low-oxygen environment to melt out the pure copper, a process known as smelting. This lent more flexibility to copper crafting; no longer was native copper the only kind of useful copper if copper could be extracted from ores.

Innovative Egyptians Copper mirror with wood handle from the Egyptian Middle Kingdom (c. 2000-1500 B.C.) or later. Credit: Hood Museum of Art, Dartmouth College; Gift of the Estate of Harold Goddard Rugg, Class of 1906 The Sumerians and the Chaldeans living in ancient Mesopotamia are believed to be the first people to make wide use of copper, and their copper crafting knowledge was introduced to the ancient Egyptians. The Egyptians mined copper from Sinai and used it to make agricultural tools such as hoes and sickles, as well as cookware, dishes, and artisans' tools such as saws, chisels, and knives. The Egyptians, famously fond of personal beautification, made mirrors and razors out of copper and produced green and blue makeup from malachite and azurite, two copper compounds with brilliant green and blue colors. By comparing the purity of copper artifacts from both Mesopotamia and Egypt, scientists have determined that the Egyptians improved upon the smelting methods of their northern neighbors in Mesopotamia. Most copper items in Egypt were produced by casting molten copper in molds.

The Egyptians appear to have been one of several groups that independently developed the lost-wax method of casting, which is still used today. (Put simply, wax is formed into the shape of the end product, then covered in clay. The wax is melted out leaving a clay mold, which is then filled with molten copper. The mold is broken off when the metal is cool.) Bronze is Better The Egyptians may have been the first group to discover that mixing copper with arsenic or tin made a stronger, harder metal better suited for weapons and tools and more easily cast in molds than pure copper. (Since copper ore often contains arsenic, this may have been the unintentional result of smelting copper ore that included naturally occurring arsenic.) This alloy of copper with arsenic or tin is called bronze, and there is archeological evidence that the Egyptians first produced bronze in 4,000 B.C. Bronze may have also been developed independently in other parts of the Middle East and other parts of the world. Regardless of where it originated, bronze metallurgy soon overtook copper in many parts of the globe, thus ushering in the Bronze Age.

(In parts of the world that lacked deposits of tin, copper was used alone or alloyed with other metals until iron was introduced.) The smelting process for bronze made with arsenic would have produced poisonous fumes. People may have preferred tin-based bronze or found that it was easier to control the amounts of tin added to copper than it was to control the amount of arsenic, which often occurred naturally in copper ore. Whatever the reason, bronze made with tin soon became the bronze of choice throughout the Middle East. Tin deposits were more confined to certain geographical areas than copper, which was readily available in many parts of the Middle East as well as other parts of the world. As people began using bronze instead of pure copper to make weapons and tools, trade in tin developed. The availability of bronze led to more advanced tool and weapon making, and with better weapons, armies could better conquer neighboring societies (and plunder their tin and copper resources). Early-Middle Bronze Age (2700-1600 BCE) bronze rat-tang dagger blade from Cyprus.

Credit: Hood Museum of Art, Dartmouth College; Bequest of Emily Howe-Hitchcock The island of Cyprus in the Eastern Mediterranean was a major destination for European and Middle Eastern Bronze Age people looking to buy or loot copper. Cyprus was the major supplier of copper to the Roman Empire. The name copper is probably derived from the Latin aes Cyprium, meaning metal of Cyprus. However, some speculate that the name Cyprus may have come second; it may have been derived from an older word for copper. Copper Crafting and Spirituality As copper helped humans to advance warfare, it also has played a role in the religious and spiritual life of people around the world through time. Hathor, Egyptian goddess of the sky, music, dance and art, was also the patron of Sinai, the major copper mining region of the Egyptians; she was often referred to as Lady of Malachite. To the people of the Andes in South America, who developed the most advanced metallurgy in pre-Columbian America, copper metallurgy was more than a secular craft for producing tools.

Using native copper, Andean artisans made religious items from pounded copper foil and gilded copper. Woman's anklet/divination implement made from copper alloy by the Senufo People from Ivory Coast, Africa, 19th century. Credi: Hood Museum of Art, Dartmouth College; Gift of Arnold and Joanne Syrop In many pre-colonial sub-Saharan cultures as well, coppersmiths were believed to have powers as shamans, magicians, and priests because of their intimate knowledge of earth, minerals, and fire and their ability to produce metal from ore. In some parts of the continent coppersmithing was an inherited position with master smiths passing secret knowledge on to their sons. Mining, smelting, and casting of copper ore were preceded by elaborate ceremonies to ensure that the endeavors were safe and fruitful. Copper also plays a role today in many New Age beliefs. In some modern religions, it is seen as having healing powers, both spiritually and physically. Some people wear copper to help alleviate the symptoms of arthritis. Bronze Buddhas and Copper Cash 7th century bronze Dipankara Buddha from India. Credit: Hood Museum of Art, Dartmouth College; Gift of Paul E.

Manheim The people of the Indian subcontinent have been using copper and its alloys as long as anyone. Bronze casting was extensive in ancient times and bronze was used for religious statues and artwork. This practice also spread to Southeast Asia where copper and its alloys are used extensively even today in Buddhist artwork. Copper was first used in China around 2500 BC. The Chinese quickly began using bronze as well, and used different percentages of tin in bronze for different purposes. They used copper and bronze extensively for coinage. During the flourishing economic activity and expanded foreign trade in the Sung dynasty, circa 900 to 1100 AD, the use of cashround copper coins with a square hole in the middleexploded. Copper production was now reaching almost industrial proportions in some civilizations, though probably nowhere more than in ancient Rome. The Romans: Precocious Polluters Although iron and lead were in use by the era of the ancient Romans, copper, bronze, and brass (an alloy of copper and zinc) were used by the Romans for coins, aspects of architecture such as doors, and some parts of their extensive plumbing system (although pipes were made of lead). They also developed pipe organs made with copper pipes.

Roman copper coin in the denomination of "As", from the reign of Caligula, c. 37-38 A.D. Credit: Hood Museum of Art, Dartmouth College; Gift of Arthur Fairbanks, Class of 1886 The Romans controlled extensive copper deposits throughout their empire. Scientists analyzing copper isotopes and trace metals present in Roman copper coins have determined that Rio Tinto, Spain (still a working copper mine), Cyprus, and to a lesser extent Tuscany, Sicily, Britain, France, Germany and other parts of Europe and the Middle East were sources of copper for the Empire. Increased purity of Roman copper coins over time also shows that their smelting methods improved quickly. The Romans in their heyday produced nearly 17,000 tons of copper annually, more than would be produced again until the Industrial Revolution in Europe. With this enormous output of copper came pollution that would be unsurpassed for almost two thousand years when the Industrial Revolution began. Did polluted air from early copper smelting affect the health of humans living in ancient times? Probably. Early smelting methods at that time were crude and inefficient by the standards of today.

Copper smelting and to a lesser degree copper mining produced ultra-fine particle dust that was carried into the atmosphere on air currents created by the intense heat from smelting operations. Most of the pollution would have fallen near the smelting sites, causing health problems and contaminating soil and water. Roman Bronze waterspout from 2nd century A.D. Credit: Hood Museum of Art, Dartmouth College; Gift of Leo A. Marantz, Class of 1935 Scientists in the 1990s discovered that copper contamination is present in 7,000-year-old layers of ice in the Greenland glacial caps. A layer of ice is deposited on glacial caps annually, allowing a year-by-year analysis of the ice composition. As copper smelting became widespread at the beginning of the Bronze Age, enough copper was released into the air to contaminate ice thousands of miles away. Peaks in copper concentrations in ice layers correspond to the era of the Roman Empire, the height of the Sung dynasty in China (c.

900-1100 AD), and the Industrial Revolution, with decreased concentrations found in ice deposited immediately after the fall of the Roman Empire and during the later Middle Ages of Europe, when copper and bronze use was lower. The copper pollution of the Roman days still haunts us today. One former Roman copper mine and smelting site in Wadi Faynan, Jordan is still  two thousand years after it ceased operations  a toxic wasteland littered with slag from copper smelting. Researchers have discovered that vegetation and livestock in Wadi Faynan today have high copper levels in their tissue. The Industrial Revolution: Picking up Where the Romans Left Off Beginning in the late 1600s, copper smelting became a major industry in Great Britain. Copper ore from Cornwall and other areas and coal deposits throughout the country fueled the smelting of copper. An abundance of coal in Swansea, Wales made this coastal town a prime location for Britain's copper smelting activities beginning in early 1700s. The copper industry drove the economy of this town. Wealthy English people often owned smelters, while local Welsh people worked as laborers in the industry.

Just as in ancient Rome, copper smelting had its price. The town and once lush countryside surrounding Swansea was stripped of vegetation by noxious copper smoke that billowed from the smelter stacks and settled on the surrounding town and fields. Topsoil on denuded hillsides succumbed to erosion. Livestock developed strange new ailments like swollen joints and rotten teeth. Farmers blamed the smoke. The smoke also reportedly caused shortness of breath, decreased appetite, and other complaints in humans. The Cornish copper ore purified in the Swansea smelters was high in arsenic, sulfur, and fluorspar (a compound of the element fluorine). The smelters emitted fumes from these compounds along with exhaust from the coal that fired the operations. The sulfur and fluorspar from the smoke mixed with water and oxygen in the atmosphere to produce sulfurous, sulfuric and hydrofluoric acids which rained down on Swansea as acid rain. Copper slag and other waste covered the landscape near the smelters.

Historic print of 18th century copper smelting in the lower Swansea Valley In 1821, a fund was set up in Swansea, with contributions from some of the smelter owners, that would go to whomever could develop the technology to reduce the level of poisons being emitted from the smelters. (The industrialists were likely more concerned with economics and aesthetics than the health of workers and local people.) Although several groups of people came up with ideas to purify the smoke, none succeeded. Eleven years later, a group of Welsh farmers from outside Swansea sued one of the major smelter owners for public nuisance, claiming that the smelter smoke was damaging their farms. The owner of the copper smelter hired one of the best lawyers in the country, who fought the plaintiffs on the basis that the town depended on the copper industry for its economic survival and that the crop failures and sick livestock were the result of the Welsh people's backward farming methods and the disagreeable Welsh weather. The farmers lost the suit. Conductive Copper Copper played a central role in the technologies developed during the industrial revolution. One of the most important uses of copper at that time was in electrical engineering.

Early scientists experimenting with electricity chose copper as a transmitter because it is highly conductive (can transmit electrical current easily). The electrical engineering industry today is the second largest consumer of copper. The Price of Industrialization Although production methods have improved since the time of the Romans and the Industrial Revolution, today copper production makes a hefty contribution to global pollution. Butte, Montana is home of an abandoned copper mine once owned by the now defunct Anaconda Copper Mining Company, established in Butte in 1895. Until the major Butte mine operations closed in the 1980s, the mine produced 20 billion pounds of copper. Until the 1950's, it produced one third of the country's copper and was an important supplier for the nation during the two World Wars. The former mine is now the largest Superfund site in the country. The main open pit has filled with water since the termination of mining activities, forming a 600-acre lake. Copper, lead, cadmium and arsenic contaminate the huge pit, which is recharged with water every day from an aquifer belowmaking the toxic lake nearly impossible to clean up.

Sulfur, a mineral that is commonly a component of copper ore, reacts with air and water, producing sulfuric acid, which fills the pit. Mine runoff and fallout from the smelter once owned by Anaconda cover the landscape. A 1,000-acre tailings pond sits near the main pit. The Berkeley Pit, Butte Montana. Photo copyright 2000 by Anthony Leiserowitz. Used with permission During its operation, the copper mine in Butte shaped the social fabric of the town. Anaconda Copper Mining Company had a heavy hand in Montana politics and had a direct effect on the lives of miners and their families. Life in Butte during most of the 20th century revolved around anticipating layoffs and strikes that came at the end of three-year contracts between Anaconda Company and the miners' union. Working conditions were terrible. Mining accidents, miners' lung, heavy pollution, and violence and unrest between unions and the company were some of the costs to the people of Butte. Although little copper mining is still going on in the town, citizens of Butte are left with the toxic legacy of the mine.

The Anaconda Company also owned a massive copper mine in Chuquicamata, Chile that operated from the 1920s to the 1970s. Chilean mine laborers lived in tiny company-owned apartments with minimal plumbing facilities. Wives and family of miners waited in lines daily for access to the meager provisions at the company store designated to the lowest class of mine employees. Their employment status also dictated which schools their children could attend. Strikes were also a regular part of life for miners and their families. Ethnographer and Butte, Montana native Janet Finn writes, In establishing labor, community, and government relations in Chuquicamata, the company turned to tried and true methods practiced in Butte: blacklists, bribery, and occasional brute force tempered with amusements that embraced both vice and virtue. Anaconda Company's Chuquicamata mine was closed in 1971 after the Chilean government nationalized the country's copper resources. However, copper mining is still a major industry in Chile.

A University of Chile study in 1999 showed that copper mining, smelting, and refining accounts for a significant portion of the greenhouse gas production and other air pollution in that country and accounts for the largest consumption of fossil fuels in Chile as well as a significant amount of electricity. This contributes to global carbon dioxide levels, which contribute to global warming. Additionally, during the smelting process, large quantities of sulfur dioxide (SO2), a precursor to acid precipitation, are released from the sulfide ores, the most commonly mined copper ores in Chile. Local Copper Mining Historic photo of the Elizabeth Mine, Strafford, VT. Photo source: "The Legacy of the Elizabeth Mine" website Several towns in central Vermont's Orange County were sites of small copper mines and smelting operations during the 1800's. None of the mines produced as much copper as the major mines in other parts of the country, but the local mines were a source of employment for Cornish and Irish immigrants and helped support the local economy.

Ely (now Vershire) was a classic boom and bust mining town, the site of one of the larger copper mines in the area and the scene of two Ely Wars between miners and mine owners in which miners rioted to get back-pay owed to them by the failing mining company. Another local copper mine was the Elizabeth Mine in South Strafford, Vermont that was in operation from 1830 to 1958. Today, it is part of the Environmental Protection Agency's Superfund program. Sources Include: Green Mountain Copper: The Story of Vermont's Red Metal by Collamer Abbott, published by the Herald Printery, Randolph, Vermont, 1973. Red Gold of Africa by Eugenia W. Herbert, published by the University of Wisconsin Press, Madison, 1984. Early Central Andean Metalworking from Mina Perdida, Peru by Richard L Burger and Robert B Gordon in Science, New Series, Vol. 282, No. 5391, pages 1108-1111, November 6, 1998.

Sixty Centuries of Copper by B Webster Smith, published by Hutchinson of London for the Copper Development Association, 1965. Cyprus Lives in Love & Strife by Robert Wernick in Smithsonian, Vol. 30, Issue 4, July 1999. Copper, Prized Through the Ages, by Jeffrey A Scovil in Earth, Vol. 4, Issue 2, April 1995. Copper by Donald G Barceloux in Clinical Toxicology, Vol. 37, No. 2, pages 217230, 1999. Ancient Metal Mines Sullied Global Skies by R Monastersky in Science News, Vol. 149, Issue 15, April 13, 1996. Long Term Energy-Related Environmental Issues of Copper Production by S Alvarado, P Maldonado, A Barrios, I Jaques in Energy, Vol. 27, Issue 2, pages 183-196, February 2002.

How Rome Polluted the World by David Keys in Geographical, Vol. 75, Issue 12, December 2003. The Great Copper Trials by Ronald Rees in History Today, Vol. 43, Issue 12, December 1993. Arsenic Bronze: Dirty Copper or Chosen Alloy? A View from the Americas, by Heather Lechtman in Journal of Field Archaeology, Vol. 23, No. 4, pages 477-514, Winter, 1996. A Penny for Your Thoughts: Stories of Women, Copper, and Community by Janet L Finn in Frontiers, Boulder, CO, Vol.19, Issue. 2, page 231, 1998. Pennies from Hell by Edwin Dobb in Harper's Magazine, Vol. 293, Issue 1757, October 1996. Atmospheric Pollution and the British Copper Industry, 1690-1920 by Edmund Newell in Technology and Culture, Vol. 38, No.

3, pages 655-689, July 1997.

Question: Which alloy is created using copper and tin?
Answer: BRONZE